Is there anything unusual about it? For example, is it lacking HDMI ports?
(Actually, even if it is lacking HDMI ports, it may not affect your Roku model choice, since all Rokus made in the last 5 years or more years have been HDMI-only anyway. Meaning any modern Roku would need a convertor if the TV has no HDMI ports.)
You wouldn’t need a 4K model, though most would suggest you get one anyway. Not just for the 4K-ness but because the 4K models don’t cost much more and have generally more capable hardware – faster UI, less likely to have trouble supporting later updates etc.
Banned but back. Because why not?